Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux.
It’s distribution independent package format and the main contributor is Fedora project team. The Flatpak framework is adopted by most of the major Linux distributions.
It provides a sandbox (isolated) environment to run the app and it doesn’t impact either other apps and distribution core packages.
This is the new stable series, ending the 1.3.x series. The major changes since the 1.2.x is the improved I/O use for system-installed applications, and the new format for pre-configured remotes.
If you would like to learn about Flatpak, Refer the following link.
Changes in 1.4.0?
Recalculate download-size when moving between repos in build-commit-from.
New library error FLATPAK_ERROR_REF_NOT_FOUND returned instead of G_IO_ERROR_NOT_FOUND.
Fix installed tests when running on a tty.
Fix a double-set of a GError.
Grant more permissions on the /run/host/monitor directory to work with e.g. toolbox on the host.